From your earlier post, I suppose your target device has the NTFS file system. It is possible to mount NTFS in CentOS-4 but it requires some extra steps. The current version of CentOS wiki on NTFS no longer has instructions for CentOS-4. However if you go back to an old page like [url=http://wiki.centos.org/TipsAndTricks/NTFS?action=recall&rev=23]this one from 2007[/url], you can see the description for CentOS-4. I think/hope that the rpmforge repository still carries the required packages.

If this is really "urgent" it might be even quicker if you just install CentOS-5. But it's your call.